Can a flat roof survey tell me if my insulation is adequate?
Not necessarily. A visual survey may identify information about the apparent roof build-up, but it cannot reliably confirm the condition, moisture content or thickness of concealed insulation. Where this information is required, further investigation such as core sampling may be necessary. The applicable thermal requirements also depend on factors including the building, the work being undertaken and which Building Regulations provisions apply.
Can I walk on Deck-VQ® vacuum insulation panels?
Yes, this is possible due to the protection layers in high density PIR and the compressive strength of 150 kPa (CS(10\Y)150). Deck-VQ® is suitable for application in flat roofs and terraces, subject to light foot traffic.
As for every type of insulation, we recommend to limit the foot traffic during installation to a minimum and apply the waterproofing as soon as possible after installation. It is best practice to only install the area you are able to insulate AND waterproof in one day.
Can tapered insulation be used on an existing flat roof?
Yes. Tapered insulation can be designed for both new and existing roofs.
For refurbishment projects, the existing roof construction should be assessed before a tapered insulation scheme is designed. The survey and design should consider the existing roof dimensions, drainage points, falls, obstructions, roof condition and the proposed new roof build-up.
Can you drill, nail or saw into a Vacuum Insulation Panel?
No, because these actions will lead to the loss of vacuum in the VIP and reduce the thermal performance by a factor of three*.
Our Deck-VQ® concept offers an optimum protection to prevent most damage on site. (see “What is the difference between Deck-VQ® and a Vacuum Insulation Panel?”).
Our technical services provide guidance and deliver a detailed design for your project.
Do not hesitate to contact us for further information.
*The thermal conductivity of the core material rises to ca. 0,020 W/mK under ambient pressure.
Do I need an intrusive survey or core samples?
Not every roof survey requires intrusive investigation. If the purpose is to identify visible defects or drainage issues, a visual assessment may be sufficient. However, where the condition of the underlying roof build-up, moisture levels or insulation needs to be established, intrusive investigation may be recommended. The appropriate scope will depend on the condition of the roof and the reason for the survey.
How can I improve the thermal performance of an existing flat roof?
Improving an existing flat roof's thermal performance may involve adding insulation as part of a refurbishment or overlay system, subject to the condition and construction of the existing roof.
The appropriate solution depends on factors such as:
- Existing roof construction
- Existing waterproofing
- Available build-up height
- Required U-value
- Moisture and condensation considerations
- Drainage
- Existing roof condition
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Upstands and junctions
Where available space is restricted, high-performance insulation such as vacuum insulation can provide an option for achieving improved thermal performance without requiring the same thickness as some conventional insulation products. Gradient's Deck-VQ® has been used in refurbishment projects where existing roof height and parapet constraints limited the available build-up.
How do I prevent thermal bridging through a flat roof?
Thermal bridging occurs where heat can flow more readily through part of a building element because of a change in material, geometry or construction.
In a flat roof, thermal bridging can occur around areas such as junctions, penetrations, parapets, rooflights and structural elements.
Good design should aim to maintain continuity of insulation wherever possible and address junctions and details appropriately.
The thermal performance of the complete roof build-up should be assessed rather than considering the insulation product in isolation. Accurate U-value calculations can help determine the thermal performance of the proposed construction. Gradient states that its U-value calculations are based on the relevant calculation methodology, including BS EN ISO 6946 for building elements.
How is a tapered insulation scheme designed?
A tapered insulation scheme is designed around the geometry and drainage requirements of the individual roof.
The design process should consider factors such as:
- Roof dimensions and geometry
- Drainage outlets and gutters
- Existing falls and backfalls
- Rooflights and other obstructions
- Required insulation performance
- The structural deck
- Waterproofing system
- Required roof build-up
-
Upstands and perimeter details
Gradient provides a design service that produces a pre-designed, dimensionally accurate tapered insulation solution with detailed layout drawings.
What happens if a vacuum insulation panel is damaged?
Damage that penetrates the vacuum insulation panel can cause the vacuum to be lost, reducing its thermal performance.
For this reason, vacuum insulation panels should not be drilled, nailed or sawn.
Gradient specifically states that drilling, nailing or sawing a Vacuum Insulation Panel can cause loss of vacuum and reduce thermal performance. Deck-VQ® incorporates protective high-density PIR layers designed to provide additional protection to the vacuum panel during installation and use.
Installers should follow the manufacturer's installation instructions and avoid activities that could damage the panels.
What is a Vacuum Insulation Panel or VIP?
VIP is the abbreviation of Vacuum Insulation Panel. A Vacuum Insulation Panel generally comprises a microporous core material (e.g. based on fumed silica), which is introduced into a high barrier multilayer foil envelope. The envelope is then evacuated and sealed, obtaining a near vacuum inside the envelope.
Because of the microporous core and the absence of air, excellent thermal properties are obtained. For our Vacuum Insulation Panel as such (Core-VQ®) we can declare a lambda value of 0,006 W/mK, which is typically 3-5 better than traditional insulation materials.
Vacuum Insulation Panels have already been used for several decades in high demanding applications, especially when stringent requirements for thermal insulation are set (e.g. refrigerators). As the thermal insulation of buildings has become increasingly important over the last years, Vacuum Insulation Panels have been introduced in buildings to meet the high standards.
Recticel Insulation offers the following products:
